FIG. 1 shows a conventional electric nail gun 1 disclosed in Taiwanese Invention Patent No. 1385059. The conventional electric nail gun 1 includes a supporting bracket 11, a flywheel 12 rotatably disposed on the supporting bracket 11 and capable of being electrically driven to rotate, a swing arm 13 pivotally disposed on the supporting bracket 11 and movable toward or away from the flywheel 12, a guiding rod 14 co-movably connected to the swing arm 13 and extending in a nail-striking direction (Y), an impact member 15 in contact with and slidable along the guiding rod 14, and two sliding wheels 16 rotatably disposed on the impact member 15 and in rolling contact with the swing arm 13. When the swing arm 13 is moved toward the flywheel 12 by an external force and the impact member 15 contacts the flywheel 12, the impact member 15 slides at a high speed along the guiding rod 14 in the nail-striking direction (Y) for performing a nail-striking operation.
The sliding wheels 16 improve smoothness in movement of the impact member 15 along the guiding rod 14. However, since the impact member 15 and the guiding rod 14 are in physical contact with each other, frictional resistance is generated between the impact member 15 and the guiding rod 14 during the sliding movement of the impact member 15. Therefore, there is still room for improving the smoothness of the movement of the impact member 15.